Rücktitelbild: Synthesis, Structures and Properties of Trioxa[9]circulene and Diepoxycyclononatrinaphthalene (Angew. Chem. 23/2024)

A 9-membered ring is incorporated into a saddle-shaped π-skeleton: In their Research Article (e202402756), Qian Miao et al. report the synthesis of trioxa[9]circulene through intramolecular oxidative coupling of dimethoxydioxa[8]helicene. In the crystals, molecules of trioxa[9]circulene stack in a column with remarkable π–π overlap, resembling the stacking pattern of saddle-shaped potato chips. Dimethoxydioxa[8]helicene exhibits high absorption and luminescence dissymmetry factors on the order of 10−2.